Red Shift and the Expanding Universe

The video explains how scientists know the universe is expanding by measuring red shift in light from galaxies. The Doppler effect is demonstrated using sound waves to show how wavelengths change with movement. Red shift indicates galaxies moving away, while blue shift shows them moving closer. The further a galaxy is, the greater its red shift, suggesting faster movement. This supports the theory that the universe began 13.7 billion years ago with the Big Bang.

What is the primary evidence that the universe is expanding?

• The presence of black holes

• The blue shift observed in light from galaxies

• The existence of dark matter

• The red shift observed in light from galaxies

What phenomenon is used to explain the change in pitch of a sound as a car passes by?

• The gravitational pull

• The blue shift

• The red shift

• The Doppler effect

How does the Doppler effect relate to light waves from galaxies?

• It makes light waves travel faster

• It has no effect on light waves

• It changes the color of light waves

• It causes light waves to disappear

What happens to light waves from a galaxy moving away from us?

• They become invisible

• They become blue shifted

• They become red shifted

• They remain unchanged

What does a blue shift in light from a galaxy indicate?

• The galaxy is moving towards us

• The galaxy is stationary

• The galaxy is expanding

• The galaxy is moving away from us

What does the red shift in light from distant galaxies tell us?

• Galaxies are shrinking

• Galaxies are moving away from us

• Galaxies are stationary

• Galaxies are moving towards us

What is the relationship between a galaxy's distance and its red shift?

• Red shift is random

• Distance has no effect on red shift

• Closer galaxies have a larger red shift

• Further galaxies have a larger red shift

What major event is believed to have started the universe?

• The Big Freeze

• The Big Crunch

• The Big Rip

• The Big Bang

How long ago did the Big Bang occur?

• 4.5 billion years ago

• 20 billion years ago

• 13.7 billion years ago

• 10 billion years ago

What additional evidence supports the Big Bang theory?

• Background radiation

• The existence of dark matter

• The presence of asteroids

• The presence of black holes